Temperature control method, control device and storage medium

Abstract

This invention relates to a temperature control method, control device, and storage medium. The method includes: acting on a heating device, including: acquiring an initial duty cycle of the heating device and a control sensitivity coefficient of the heating device at a target temperature, wherein the control sensitivity coefficient reflects the relationship between the initial duty cycle of the heating device and the target temperature; determining algorithm coefficients in a proportional-integral-differential algorithm for the heating device at the target temperature based on the initial duty cycle and the control sensitivity coefficient, wherein the target temperature is a target desired temperature reached by the heating device after heating in response to a user operation; and adjusting the current temperature of the heating device based on the algorithm coefficients and using a proportional-integral-differential algorithm to make the current temperature reach the target temperature.

Description

Technical Field

[0001] This invention relates to the field of temperature control technology, and specifically provides a temperature control method, control device, and storage medium. Background Technology

[0002] In existing temperature control technologies, proportional-integral-derivative (PID) control is a commonly used method. However, in PID control, the proportional, integral, and derivative coefficients need to be precisely set to achieve accurate temperature control of the equipment.

[0003] However, in existing technologies, finding the optimal PID parameters for each target temperature often requires extensive experimentation and adjustment. This method not only consumes a lot of time and resources, but also makes it difficult to guarantee that the optimal parameters will be found in every experiment.

[0004] Accordingly, a new temperature control solution is needed in this field to address the aforementioned problems. Summary of the Invention

[0005] To overcome the above-mentioned deficiencies, the present invention is proposed to provide a solution, or at least a partial solution, to the problem of the difficulty in finding the proportional-integral-differential equation in the prior art.

[0006] In a first aspect, the present invention provides a temperature control method applied to a heating device, comprising: acquiring an initial duty cycle of the heating device and a control sensitivity coefficient of the heating device at a target temperature, wherein the control sensitivity coefficient reflects the relationship between the initial duty cycle of the heating device and the target temperature; determining algorithm coefficients in a proportional-integral-differential algorithm for the heating device at the target temperature based on the initial duty cycle and the control sensitivity coefficient, wherein the target temperature is a target desired temperature reached by the heating device after heating in response to a user operation; and adjusting the current temperature of the heating device based on the algorithm coefficients and using a proportional-integral-differential algorithm to achieve the target temperature.

[0007] As an alternative or supplement to the above scheme, in a method according to an embodiment of the present invention, the algorithm coefficients include at least one of a first proportional coefficient, a first integral coefficient, and a first derivative coefficient. Determining the algorithm coefficients in the proportional-integral-derivative algorithm of the heating device at the target temperature based on the initial duty cycle and the control sensitivity coefficient includes: determining a duty cycle threshold based on the control sensitivity coefficient; and determining the algorithm coefficients based on the relationship between the initial duty cycle, the control sensitivity coefficient, and the duty cycle threshold.

[0008] As an alternative or supplement to the above scheme, in a method according to an embodiment of the present invention, the duty cycle threshold includes a first duty cycle threshold and a second duty cycle threshold, wherein the first duty cycle threshold is less than the second duty cycle threshold. Determining the algorithm coefficient based on the relationship between the initial duty cycle, the control sensitivity coefficient, and the duty cycle threshold includes: when the initial duty cycle is greater than a preset first duty cycle threshold and less than a preset second duty cycle threshold, determining a first proportional coefficient based on the duty cycle, the sensitivity coefficient, and the following formula:

[0009] Kp = k1 × Sen + k2 × Y,

[0010] Where k1 and k2 are constant terms, Kp is the first proportional coefficient, Sen is the control sensitivity coefficient, and Y is the initial duty cycle; and / or, when the duty cycle is greater than the first duty cycle threshold and less than the second duty cycle threshold, the first differential coefficient is determined to satisfy the following formula based on the duty cycle, the sensitivity coefficient, and the following formula:

[0011] Kd = (k4 / Sen) × Y + k5, where k4 is a constant term, Kd is the first proportional coefficient, and Y is the initial duty cycle.

[0012] As an alternative or supplement to the above scheme, the duty cycle threshold includes a first duty cycle threshold and a second duty cycle threshold, wherein the first duty cycle threshold is less than the second duty cycle threshold. Determining the algorithm coefficient based on the relationship between the initial duty cycle, the control sensitivity coefficient, and the duty cycle threshold includes: when the initial duty cycle is less than or equal to the preset first duty cycle threshold, and / or greater than or equal to the second duty cycle threshold, the first proportional coefficient is determined based on the control sensitivity coefficient and the following formula:

[0013] Kp = k6 × Sen,

[0014] Where k6 is a first preset constant term, wherein the value of k6 when the initial duty cycle is less than or equal to the first duty cycle threshold is less than the value of k6 when the initial duty cycle is greater than or equal to the second duty cycle threshold; Kp is a first proportional coefficient, Sen is a control sensitivity coefficient; and / or, when the initial duty cycle is less than or equal to the first duty cycle threshold, and / or greater than or equal to the second duty cycle threshold, the first differential coefficient satisfies:

[0015] Kd = k7

[0016] Where k7 is the second preset constant term, and Kd is the first proportional coefficient; wherein, when the initial duty cycle is less than or equal to the first duty cycle threshold, the value of k7 is less than the value of k7 when the initial duty cycle is greater than or equal to the second duty cycle threshold.

[0017] As an alternative or supplement to the above scheme, the first integral coefficient is determined based on the relationship between the initial duty cycle and the duty cycle threshold; the first integral coefficient is then used to determine the following formula:

[0018] Ki = Kp / k3,

[0019] Where k3 is a constant term, Ki is the first proportionality coefficient, and Kp is the first proportionality coefficient.

[0020] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, obtaining the control sensitivity coefficient of the heating device at the target temperature includes: obtaining the first derivative of the initial duty cycle of the heating device with respect to the target temperature, and using the first derivative as the control sensitivity coefficient.

[0021] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, before adjusting the current temperature based on the algorithm coefficients and using a proportional-integral-differential algorithm to bring the current temperature to the target temperature, the method further includes: responding to a control command to heat to the target temperature, performing heating at full load power; determining whether the absolute value of the difference between the current temperature and the target temperature is less than or equal to a first preset threshold; if the absolute value of the difference between the current temperature and the target temperature is less than or equal to the first preset threshold, then executing the step of "adjusting the current temperature based on the algorithm coefficients and using a proportional-integral-differential algorithm to bring the current temperature to the target temperature". The process involves "regulating the temperature"; and / or, after regulating the current temperature based on the algorithm coefficients and using a proportional-integral-differential algorithm, the process further includes: determining whether the absolute value of the difference between the current temperature and the target temperature is less than or equal to a second preset threshold within a preset time period; if so, determining that the process has entered a stable phase; when entering a stable phase, using a proportional-integral-differential parameter combination different from the regulation phase of "regulating the current temperature based on a proportional-integral-differential algorithm" for temperature control, wherein at least one parameter in the proportional-integral-differential parameter combination has a value less than the value of the corresponding parameter in the regulation phase.

[0022] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, the step of regulating the current temperature based on the algorithm coefficients and using a proportional-integral-differential (PID) algorithm includes: determining an initial value of the cumulative deviation in the PID algorithm according to the ratio of the initial duty cycle and the preset integral parameter; regulating the current temperature using the PID algorithm based on the initial value of the cumulative deviation and the algorithm coefficients; and / or, the step of using a PID parameter combination different from the regulation stage of regulating the current temperature based on the PID algorithm for temperature control includes: using a first PID parameter combination for temperature control when the absolute value of the difference between the current temperature and the target temperature is less than or equal to a second preset threshold; using a second PID parameter combination for temperature control when the absolute value of the difference between the current temperature and the target temperature is greater than the second preset threshold and less than or equal to a third preset threshold, wherein at least one parameter in the second PID parameter combination has a value greater than the value of the corresponding parameter in the second PID parameter combination.

[0023] In a second aspect, a control device is provided, comprising a processor and a storage device, the storage device being adapted to store a plurality of computer programs, the computer programs being adapted to be loaded and run by the processor to perform the temperature control method described in any of the above-described temperature control methods.

[0024] In a third aspect, a computer-readable storage medium is provided, wherein a plurality of computer programs are stored therein, the computer programs being adapted to be loaded and run by a processor to perform the temperature control method described in any of the above-described temperature control methods.

[0025] In a fourth aspect, a heating device is provided, including a temperature sensor and a control device, wherein the temperature sensor is used to detect the current temperature inside the heating device; and the control device is used to execute the temperature control method described in any of the above-mentioned technical solutions.

[0026] The present invention comprises one or more of the following technical solutions: Beneficial effects:

[0027] In implementing the technical solution of this invention, the algorithm coefficients of the heating equipment at the target temperature are determined by obtaining the initial duty cycle of the heating equipment and the control sensitivity coefficient at the target temperature. In this way, this technology not only reduces reliance on experiments, saving time and resources, but also dynamically adjusts the PID parameters according to different equipment states and target temperatures, thereby achieving precise temperature control of the equipment and improving its temperature regulation effect. Attached Figure Description

[0028] The disclosure of this invention will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Furthermore, similar numbers in the drawings are used to denote similar components, wherein:

[0029] Figure 1 This is a schematic flowchart of the main steps of a temperature control method according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic flowchart of the minor steps of a temperature control method according to an embodiment of the present invention. Detailed Implementation

[0031] Some embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0032] In the description of this invention, "module" and "processor" can include hardware, software, or a combination of both. A module can include hardware circuitry, various suitable sensors, communication ports, memory, and may also include software components, such as computer programs, or a combination of software and hardware. A processor can be a central processing unit, microprocessor, image processor, digital signal processor, or any other suitable processor. The processor has data and / or signal processing capabilities. The processor can be implemented in software, in hardware, or a combination of both. Non-transitory computer-readable storage media includes any suitable medium capable of storing computer programs, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and can include only A, only B, or A and B. The singular terms "a" or "this" can also include plural forms.

[0033] See appendix Figure 1 , Figure 1 This is a schematic flowchart illustrating the main steps of a temperature control method according to an embodiment of the present invention. Figure 1 As shown, the temperature control method in this embodiment of the invention mainly includes the following steps S10-S30.

[0034] Step S10: Obtain the initial duty cycle of the heating device and the control sensitivity coefficient of the heating device at the target temperature.

[0035] In this embodiment, the initial duty cycle reflects the duty cycle of the heating device calculated at the target temperature, and the control sensitivity coefficient reflects the relationship between the initial duty cycle of the device and the set target temperature.

[0036] In one implementation, the control sensitivity coefficient is the first derivative of the device's initial duty cycle with respect to the set target temperature. As an example, the relationship between the device's initial duty cycle and the target temperature is represented by a function.

[0037] Y = f(X),

[0038] Where Y represents the initial duty cycle and X represents the target temperature. This formula yields the initial duty cycle at the target temperature. Then, by taking the derivative, we obtain the first derivative of the function, which is the control sensitivity coefficient. To calculate the control sensitivity coefficient, since we need to determine the rate of change of the initial duty cycle with respect to the target temperature, we differentiate with respect to Y:

[0039] d(Y) / d(X)=a,

[0040] Here, 'a' refers to the control sensitivity coefficient. Knowing this slope 'a' allows us to determine the sensitivity of the device. For example, if the slope is 2, it means that when the target temperature increases by 1 unit, the initial duty cycle will increase by 2 units.

[0041] In this embodiment, the relationship between the initial duty cycle and the target temperature of the device is linear. Therefore, a linear function model is used here to describe it. When no revision coefficient is available, this model can be written as:

[0042] Y = a × X + b,

[0043] Where a is the slope and b is the intercept.

[0044] Based on this model, the control sensitivity coefficient can be obtained by taking the first derivative. Since the goal is to find the rate of change of the initial duty cycle with temperature, it is necessary to differentiate with respect to Y:

[0045] d(DC) / d(Temp)=a

[0046] Here, 'a' represents the control sensitivity coefficient.

[0047] In this embodiment, when a revision factor is present, the initial duty cycle - target temperature model is described as follows:

[0048] Y = α × (a × X + b),

[0049] Where α is the correction coefficient, first expanding the original expression yields:

[0050] Y = α*a*X + α*b.

[0051] Then, taking the derivative with respect to X, we get:

[0052] d(Y) / d(X)=α×a,

[0053] In this revised model, the control sensitivity coefficient becomes α×a.

[0054] The control sensitivity coefficient of the equipment is obtained through the above steps. This coefficient reflects the relationship between the initial duty cycle of the equipment and the target temperature. This control sensitivity coefficient can be used to determine a more accurate proportional coefficient in the PID algorithm, achieving a more convenient effect.

[0055] Step S20: Determine the algorithm coefficients of the device in the proportional-integral-derivative algorithm at the target temperature based on the initial duty cycle and the control sensitivity coefficient.

[0056] In this embodiment, the target temperature is the desired temperature reached by the device after heating in response to user operation. The algorithm coefficients include at least one of a first proportional coefficient, a first integral coefficient, and a first differential coefficient.

[0057] In one implementation, the algorithm coefficients are determined based on the relationship between the initial duty cycle, the control sensitivity coefficient, and the duty cycle threshold, wherein the duty cycle threshold is determined by the control sensitivity coefficient. The target temperature is the temperature the user desires the oven to reach. This temperature will be used as a reference point for the control system to determine how the system should adjust to achieve that set value. For example, if the user sets the target temperature to 200°C, the control system will take necessary actions (such as turning on the heating element) to raise the actual temperature inside the oven to that set value.

[0058] The Proportional-Integral-Derivative (PID) algorithm consists of three parameters: proportional (P), integral (I), and derivative (D). These parameters affect the system's control performance, such as response speed, stability, and steady-state error elimination. In this embodiment, to distinguish it from the aforementioned names, the algorithm parameters determined through calculation are referred to as the first proportional coefficient, the first integral coefficient, and the first derivative coefficient.

[0059] It should be noted that in PID control, the proportional coefficient (P), integral coefficient (I), and derivative coefficient (D) have different weights in their influence on the system. For example, in a steam oven control system, since the main objective of temperature control is to reduce the deviation between the current temperature and the target temperature, and it needs to react quickly to changes in the deviation, the proportional coefficient has the largest weight, i.e., P > I > D.

[0060] Besides providing fast response, proportional control can also prevent overshoot. Overshoot occurs when the system outputs more than the setpoint when responding to a new setpoint, causing system instability. By increasing the proportional gain, the system can be made more sensitive to deviations, thereby reducing overshoot.

[0061] Integral and derivative control play a relatively minor role in this system. Integral control is mainly used to eliminate steady-state deviations, but in a steam oven, due to the system's dynamic nature, steady-state deviations are typically small. Derivative control is mainly used to predict future deviations, but in a steam oven, because temperature changes are relatively slow, its predictive effect is limited. Therefore, in the steam oven control system, the weights of I and D are smaller than those of P.

[0062] In the tuning of a PID control system, the first and most important step is usually determining the appropriate proportional gain (P). The proportional gain plays a decisive role in the system's response speed and stability; if P is not chosen appropriately, no matter how I and D are adjusted, a good control effect cannot be obtained.

[0063] From another perspective, in the trial-and-error method, once the proportional gain is determined, I and D are adjusted according to the system's performance requirements, such as whether it's necessary to eliminate steady-state deviation, reduce overshoot, or improve response speed. Since the effects of I and D are usually smaller than P, and their effects are more subtle, adjusting I and D is generally easier once P is determined. Therefore, by determining the device's control sensitivity coefficient in advance to determine the proportional gain (P), the workload and complexity of PID parameter tuning can be greatly reduced, improving the debugging efficiency and control quality of the control system.

[0064] In this embodiment, the method for determining the first proportional coefficient, the first integral coefficient, and the first differential coefficient is given as follows.

[0065] The duty cycle threshold includes a first duty cycle threshold and a second duty cycle threshold. When the initial duty cycle is greater than the preset first duty cycle threshold and less than the preset second duty cycle threshold, the first proportional coefficient satisfies:

[0066] Kp = k1 × Sen + k2 × Y,

[0067] Where k1 and k2 are constants, Kp is the first proportional coefficient, Sen is the control sensitivity coefficient, and Y is the initial duty cycle. Both the first and second duty cycle thresholds are determined based on the control sensitivity coefficient.

[0068] In this embodiment, the initial duty cycle and control sensitivity coefficient are incorporated into the fitting relationship with the proportional gain to obtain the first proportional gain. This fitting relationship is a mathematical model fitted using experimental data. When the initial duty cycle is greater than a preset first duty cycle threshold but less than a preset second duty cycle threshold, the initial duty cycle and control sensitivity coefficient are selected as the two parameters for constructing the mathematical model. This selection is based on their characteristics, which enable good results during the fitting process. Specifically, the physical meaning of the control sensitivity coefficient is how much the initial duty cycle needs to be increased for every 1°C increase in the device's temperature. The proportional gain directly controls the change in the initial duty cycle to achieve the set target temperature. This is why both the initial duty cycle and control sensitivity coefficient are considered when constructing the proportional gain model, as they directly reflect the system's response speed and accuracy.

[0069] In this embodiment, the values ​​of both the first duty cycle threshold and the second duty cycle threshold are related to the control sensitivity coefficient. Furthermore, in this embodiment, the first duty cycle threshold and the second duty cycle threshold are set based on the system's control sensitivity coefficient to ensure that an appropriate control strategy can be adopted when the system's response to temperature changes is within a certain range.

[0070] In one implementation, for example, in this implementation, when the first duty cycle threshold is 20 Sen and the second duty cycle threshold is 100 Sen, k1 is 3.75 and k2 is 0.0625, so the corresponding mathematical model is "Kp = 0.0625 × Y + 3.75 × Sen". Substituting the initial duty cycle and the control sensitivity coefficient into the mathematical model, the first proportional coefficient at the current target temperature is obtained.

[0071] Approximately, when the initial duty cycle is greater than a preset first duty cycle threshold and less than a preset second duty cycle threshold, the first differential coefficient satisfies:

[0072] Kd = (k4 / Sen) × Y + k5,

[0073] Where k4 is a constant term, Kd is the first proportional coefficient, and Y is the initial duty cycle.

[0074] In one implementation, for example, when the first duty cycle threshold is 20 Sen and the second duty cycle threshold is 100 Sen, k4 is 7.5 and k5 is 450, so the corresponding mathematical model is "Kd=(7.5 / Sen)×Y+450". The initial duty cycle and the control sensitivity coefficient are substituted into the mathematical model to obtain the first differential coefficient at the current target temperature.

[0075] In this embodiment, the first integral coefficient and the differential coefficient are directly related, meaning there is a fixed mathematical relationship between them. Specifically, the first integral coefficient Ki can be determined by dividing the first proportional coefficient Kp by a constant term k3. In this embodiment, the first integral coefficient satisfies:

[0076] Ki = Kp / k3,

[0077] Where k3 is a constant term, Ki is the first proportionality coefficient, and Kp is the first proportionality coefficient.

[0078] In one implementation, for example, if k3 is 600, then Ki = Kp / 600.

[0079] In this embodiment, the ratio of Ki to Kp is set to a constant k3. This means that the larger the proportional coefficient Kp is, the larger the integral coefficient Ki will be, so as to accumulate and adjust the system error more quickly. Conversely, if Kp is small, Ki will also be reduced accordingly to avoid over-adjustment.

[0080] When the initial duty cycle is less than or equal to the preset first duty cycle threshold or greater than or equal to the second duty cycle threshold, the calculation formulas for the first proportional coefficient and the first differential coefficient will change.

[0081] Specifically, the first proportionality coefficient satisfies:

[0082] Kp = k6 × Sen,

[0083] Where k6 is the first preset constant term, Kp is the first proportional coefficient, and Sen is the control sensitivity coefficient. Moreover, when the initial duty cycle is less than or equal to the first duty cycle threshold, the value of k6 is less than the value of k6 when the initial duty cycle is greater than or equal to the second duty cycle threshold.

[0084] Similarly, when the initial duty cycle is less than or equal to a preset first duty cycle threshold or greater than or equal to a second duty cycle threshold, the first differential coefficient satisfies:

[0085] Kd = k7,

[0086] Where k7 is the second preset constant term, and Kd is the first proportional coefficient. When the initial duty cycle is less than or equal to the first duty cycle threshold, the value of k7 is less than the value of k7 when the initial duty cycle is greater than or equal to the second duty cycle threshold.

[0087] In one implementation, when the initial duty cycle of the device is less than or equal to a preset first duty cycle threshold, the proportional coefficient of the device in the proportional-integral-derivative (PID) algorithm at the target temperature is determined based on a control sensitivity coefficient. The initial duty cycle is not used directly here because the system exhibits relatively low sensitivity when the initial duty cycle is below the first duty cycle threshold; therefore, determining the proportional coefficient based on the control sensitivity coefficient is more appropriate.

[0088] When the initial duty cycle is less than or equal to the first duty cycle threshold, experimental observations and data analysis show that the initial duty cycle has a relatively small impact on the system, while the control sensitivity coefficient has a relatively large impact. In this case, using the control sensitivity coefficient as the primary basis for determining the proportional coefficient can improve the control effect of the PID algorithm. Preferably, when the first duty cycle threshold is 20Sen, in this embodiment, the proportional coefficient is calculated using the mathematical model "Kp = 5 × Sen".

[0089] Here's an explanation: the reason for setting the threshold is that, during PID debugging, the value of Kp will always be within a certain range. Therefore, when the initial duty cycle is less than or equal to the first duty cycle threshold, the mathematical model will also change accordingly, and the control sensitivity coefficient will be used to determine the first proportional coefficient.

[0090] When the initial duty cycle of the device is greater than a preset second duty cycle threshold, the system exhibits high sensitivity. This means that small changes can lead to large system responses. Therefore, by using a control sensitivity coefficient to calculate the first proportional coefficient, adjustments can be made based on the actual sensitivity of the system, thereby better controlling the system.

[0091] When the initial duty cycle exceeds the second duty cycle threshold, the control sensitivity coefficient plays a dominant role in determining the scaling factor. Preferably, in this embodiment, when the value of the second duty cycle threshold is 100 Sen, the scaling factor can be calculated using the mathematical model "Kp = 10 × Sen".

[0092] In this embodiment, based on the three initial duty cycle determination scenarios, the control sensitivity coefficient and the initial duty cycle or the control sensitivity coefficient alone are used to input into different mathematical models to obtain the proportional coefficient of the heating device under different initial duty cycle working environments. This makes the obtained coefficient more accurate and solves the problem of time-consuming and costly trial-and-error methods for finding the proportional coefficient in the prior art.

[0093] Step S30: Based on the algorithm coefficients and using the proportional-integral-differential algorithm, adjust the current temperature of the heating equipment to make the current temperature reach the target temperature.

[0094] In this embodiment, the current temperature is the actual temperature of the oven read by a temperature sensor inside the heating device. In this embodiment, based on the obtained algorithm coefficients, a proportional-integral-differential algorithm is used to precisely control the current temperature of the heating device in real time.

[0095] In one implementation, the current temperature of the heating device is continuously and in real-time adjusted to ensure that it ultimately reaches the set target temperature precisely. This allows the user to set the device temperature as needed, and the device can automatically adjust the temperature to meet the user's requirements.

[0096] In one implementation, the parameters in the PID controller also include integral speeds (EskAs), where the integral speed is a factor influencing the integral coefficients and determines the rate at which the system accumulates error under static error conditions. The role of this integral speed is detailed here. In this embodiment, the integral coefficients are an important part of the PID controller, helping to eliminate so-called steady-state error, which is the persistent deviation between the expected output and the actual output after the system reaches a steady state. However, excessively strong integral action can lead to overshoot and oscillations in the system. The role of the integral speed is to control this, adjusting the influence of integral control to maintain system stability while eliminating steady-state error.

[0097] For example, if the integral speed value is set to 0, the effect of integral control no longer changes. That is, the PID controller will no longer perform integral accumulation calculations, but will instead use the integral term value from the previous step. For example, when a faster response is desired and small steady-state errors are not a major concern, this setting can prevent the rapid accumulation of integral values ​​during faster responses, thus avoiding errors in subsequent judgments.

[0098] The integral velocity acts on the integral coefficient, so in this embodiment, the integral coefficient mentioned later will include the integral velocity by default.

[0099] In this embodiment, the current temperature is controlled based on the initial duty cycle and using a proportional-integral-differential algorithm. Through meticulous adjustments, the internal temperature of the heating device can accurately reach the target temperature set by the user and remain stable at this temperature.

[0100] At the beginning of the adjustment phase, a preset initial integral value is given to the PID controller, which is the initial cumulative deviation value, or the initial duty cycle. This initial duty cycle is predicted and calculated based on the stable initial duty cycle of the heating equipment at the target temperature.

[0101] The adjustment phase can be divided into one or more stages. It should be noted that in actual operation, the temperature control process may be affected by many factors, such as the dynamic characteristics of the system, changes in ambient temperature, and user operation.

[0102] In this embodiment, to address different influences, the control system preferably divides the adjustment phase into multiple sub-phases, each with its own objectives and strategies. For example, in this embodiment, the adjustment phase has three sub-phases: a "rapid adjustment" phase, a "fine-tuning" phase, and a "maintaining stability" phase.

[0103] First, the system enters a "rapid adjustment" phase, where the controller parameters are set to relatively large values ​​to quickly reduce the difference between the actual and target temperatures. After certain conditions are met, the system enters a "fine-tuning" phase, where the controller parameters are set to smaller values ​​to reduce over-adjustment and oscillations in temperature. Finally, the system enters a "maintaining stability" phase, where the controller parameters are set to moderate values ​​to maintain temperature stability.

[0104] In this embodiment, specifically, the initial duty cycle is introduced into the control through steps S401-402.

[0105] Step S401: Determine the initial value of the cumulative deviation in the proportional-integral-derivative algorithm based on the ratio of the initial duty cycle to the preset integral parameter.

[0106] In this embodiment, the cumulative deviation, also known as the integral term, represents the accumulation of all past deviation values.

[0107] In one implementation, the initial duty cycle of the device is multiplied by a preset integral parameter, and the result is the initial value of the cumulative deviation. This calculation process can be expressed as: Initial value of cumulative deviation = Initial duty cycle × Preset integral parameter.

[0108] Step S402: Based on the initial value of the cumulative deviation, the current temperature is controlled using a proportional-integral-differential algorithm.

[0109] In one implementation, the purpose of using an initial cumulative deviation value to regulate the current temperature is to prevent a large temperature rebound in the system when it first enters this stage, which would affect the steaming and baking effect.

[0110] Step S501: Determine whether the absolute value of the difference between the current temperature and the target temperature is less than or equal to the second preset threshold within a preset time period.

[0111] In this embodiment, both the preset duration and the second preset threshold can be flexibly set according to requirements.

[0112] Step S502: If yes, confirm that you have entered the stable phase.

[0113] When the temperature reaches a stable state, a different combination of proportional-integral-derivative (PID) parameters is used for temperature control compared to the control stage where the current temperature is controlled based on the proportional-integral-derivative (PID) algorithm. In this combination, at least one parameter has a value less than the corresponding parameter value in the control stage.

[0114] Similar to the adjustment phase, the stabilization phase can also have one or more sub-phases. Preferably, in this embodiment, the stabilization phase is divided into two smaller phases. Specifically, when the absolute value of the difference between the current temperature and the target temperature is less than or equal to a second preset threshold, temperature control is performed using a first proportional-integral-derivative parameter combination. In this phase, the proportional coefficient (P), integral coefficient (I), and derivative coefficient (D) are set to be smaller, mainly to minimize small temperature fluctuations, and the integral rate (EskAs) may be set to be smaller to reduce fluctuations.

[0115] When the absolute value of the difference between the current temperature and the target temperature is greater than a second preset threshold and less than or equal to a third preset threshold, temperature control is performed using a second proportional-integral-derivative (PID) parameter combination. In this combination, at least one parameter has a value greater than the corresponding parameter in the second PID parameter combination. During this stage, one or more of the proportional coefficient (P), integral coefficient (I), or derivative coefficient (D) will be appropriately increased to enable faster response and adjustment to temperature deviations. Simultaneously, the integral speed (EskAs) may be set relatively high for rapid regulation.

[0116] The stable phase is the final stage in the entire temperature control process. It's designed to maintain the oven temperature at the preset target temperature and prevent large temperature fluctuations. During this phase, the adjustment function of the PID controller is gradually weakened, especially the proportional (P) and derivative (D) controls, to avoid temperature oscillations caused by excessively rapid responses.

[0117] Here's an example. In the stabilization phase, assume the oven has reached the set temperature of 200℃ and has already undergone precise temperature adjustments during the adjustment phase. The main goal of this stabilization phase is to ensure stable oven temperature and minimize temperature fluctuations.

[0118] The stable phase is divided into two sub-phases: Phase 1 and Phase 2.

[0119] Phase 1: Phase 1 begins when the actual temperature inside the oven deviates from the target temperature within a certain range, such as ±2℃. In this phase, the primary goal is to minimize small temperature fluctuations; therefore, the proportional (P), integral (I), and derivative (D) coefficients of the PID controller may be set relatively small. For example, P could be set to 0.5, I to 1, and D to 0. Simultaneously, to eliminate small steady-state temperature differences, the integral rate (EskAs) may be set relatively small, such as 0.1.

[0120] Phase 2: If the actual temperature inside the oven deviates from the target temperature by more than ±2℃ but less than ±10℃, Phase 2 will be initiated. In this phase, a faster response and adjustment to the temperature deviation is required. Therefore, the proportional gain (P) and derivative gain (D) may be moderately increased, for example, P is set to 1, I to 1, and D to 0. Simultaneously, the integral gain (I) is set relatively large, such as 0.4.

[0121] These two stages will automatically switch based on the deviation between the actual temperature inside the oven and the target temperature, ensuring that the steam oven maintains a stable temperature throughout the cooking process.

[0122] This sophisticated control strategy enables the steam oven to maintain high precision and stable temperature control under various cooking conditions, thereby ensuring consistent cooking quality and food taste.

[0123] In this embodiment, before adjusting the current temperature based on the initial duty cycle and using the proportional-integral-differential algorithm, steps S601-602 are included, which are the heating stage of the heating device.

[0124] It should be noted that when the absolute value of the difference between the current temperature and the target temperature is greater than the third preset threshold, the system will return to the adjustment state.

[0125] Step S601: In response to the control command to heat to the target temperature, perform heating at full load power.

[0126] In one implementation, the main task of the system at this stage is to bring the heating device to the set temperature as quickly as possible. To achieve this goal, the heating element assembly used at this stage will operate at full power or maintain a high power to raise the temperature of the heating device to the target temperature as quickly as possible.

[0127] In this step, the system does not use a PID algorithm for control because speed is the most critical factor at this stage. This design aims to ensure the steam oven reaches the target temperature as quickly as possible. Therefore, the selected heating element combination will be activated and operate at maximum power to rapidly increase the internal temperature of the steam oven.

[0128] However, the specific strategy for fully opening the heating elements is controlled by the oven's "rapid heating" switch. If the "rapid heating" switch is on, the system will use the maximum power combination of heating elements to raise the temperature. If the "rapid heating" switch is off, the system will use the normal combination of heating elements to raise the temperature. But in either case, the goal at this stage is to raise the temperature as quickly as possible.

[0129] It should be noted that the heating phase ends when the current temperature of the heating device reaches the preset full-opening stop point. At this time, the current temperature will continue to rise due to inertia and then fall back. When the temperature condition meets the requirements of step S602, step S30 will be executed. The temperature setting of the full-opening stop point is positively correlated with the target temperature. In this embodiment, the relationship between the full-opening stop point and the target temperature is obtained in advance by fitting experimental data, and then the corresponding full-opening stop point is calculated based on the target temperature.

[0130] Step S602: Determine whether the absolute value of the difference between the current temperature and the target temperature is less than or equal to the first preset threshold.

[0131] In one implementation, this step is a condition for activating PID control, namely, the absolute value of the difference between the current temperature and the target temperature is less than or equal to a first preset threshold, indicating that the device temperature is approximately close to the target temperature. In this case, the system will proceed to the next step, which is to adjust the temperature based on the initial duty cycle and using a proportional-integral-derivative (PID) algorithm.

[0132] If the absolute value of the difference between the current temperature and the target temperature is less than or equal to the first preset threshold, then proceed to step S30.

[0133] It should be noted that although the steps in the above embodiments are described in a specific order, those skilled in the art will understand that in order to achieve the effects of the present invention, different steps do not necessarily have to be executed in such an order. They can be executed simultaneously (in parallel) or in other orders, and these variations are all within the scope of protection of the present invention.

[0134] Those skilled in the art will understand that all or part of the processes in the method of the above-described embodiment of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes other computer programs, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable storage medium can include any entity or device capable of carrying a computer program, media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory, random access memory, electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable storage medium can be appropriately added to or subtracted according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable storage medium does not include electrical carrier signals and telecommunication signals.

[0135] Furthermore, the present invention also provides a control device. In one embodiment of the control device according to the present invention, the control device includes a processor and a storage device. The storage device can be configured to store a program for executing the temperature control method of the above-described method embodiments, and the processor can be configured to execute the program in the storage device. The program includes, but is not limited to, the program for executing the temperature control method of the above-described method embodiments. For ease of explanation, only the parts related to the embodiments of the present invention are shown; for specific technical details not disclosed, please refer to the method section of the embodiments of the present invention. This control device can be a control device device comprising various electronic devices.

[0136] Furthermore, the present invention also provides a computer-readable storage medium. In one embodiment of the computer-readable storage medium according to the present invention, the computer-readable storage medium can be configured to store a program that performs the temperature control method of the above-described method embodiments. This program can be loaded and run by a processor to implement the above-described temperature control method. For ease of explanation, only the parts related to the embodiments of the present invention are shown; for specific technical details not disclosed, please refer to the method section of the embodiments of the present invention. The computer-readable storage medium can be a storage device device comprising various electronic devices. Optionally, in the embodiments of the present invention, the computer-readable storage medium is a non-transitory computer-readable storage medium.

[0137] Furthermore, the present invention also provides a heating device, including a temperature sensor and a control device, wherein the temperature sensor is used to detect the current temperature inside the heating device; and the control device is used to execute the temperature control method described in any of the above-mentioned technical solutions.

[0138] Furthermore, it should be understood that since the various modules are only provided to illustrate the functional units of the device of the present invention, the physical devices corresponding to these modules may be the processor itself, or a part of the processor's software, hardware, or a combination of software and hardware. Therefore, the number of modules shown in the figures is merely illustrative.

[0139] Those skilled in the art will understand that the various modules in the device can be adaptively split or combined. Such splitting or combining of specific modules will not cause the technical solution to deviate from the principles of the present invention; therefore, the technical solutions after splitting or combining will fall within the protection scope of the present invention.

[0140] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A temperature control method, characterized in that, Acting on heating equipment, including: The initial duty cycle of the heating device and the control sensitivity coefficient of the heating device at the target temperature are obtained, wherein the control sensitivity coefficient reflects the relationship between the initial duty cycle of the heating device and the target temperature; The algorithm coefficients in the proportional-integral-differential algorithm of the heating device at the target temperature are determined based on the initial duty cycle and the control sensitivity coefficient, wherein the target temperature is the target desired temperature reached by the heating device after heating in response to user operation; Based on the algorithm coefficients and using a proportional-integral-differential algorithm, the current temperature of the heating device is adjusted so that the current temperature reaches the target temperature; The algorithm coefficients include at least one of a first proportional coefficient, a first integral coefficient, and a first derivative coefficient. The algorithm coefficients in the proportional-integral-derivative algorithm for the heating device at the target temperature, determined based on the initial duty cycle and the control sensitivity coefficient, include: The duty cycle threshold is determined based on the control sensitivity coefficient. The algorithm coefficients are determined based on the relationship between the duty cycle thresholds, the initial duty cycle, and the control sensitivity coefficient. The duty cycle threshold includes a first duty cycle threshold and a second duty cycle threshold, wherein the first duty cycle threshold is smaller than the second duty cycle threshold. The algorithm coefficients are determined based on the relationship between the initial duty cycle, the control sensitivity coefficient, and the duty cycle thresholds, including: When the initial duty cycle is greater than a preset first duty cycle threshold and less than a preset second duty cycle threshold, a first proportional coefficient is determined based on the duty cycle, the sensitivity coefficient, and the following formula: Kp = k1 × Sen + k2 × Y, Where k1 and k2 are constant terms, Kp is the first proportional coefficient, Sen is the control sensitivity coefficient, and Y is the initial duty cycle; And / or, when the initial duty cycle is greater than a first duty cycle threshold but less than a second duty cycle threshold, the first differential coefficient is determined based on the duty cycle, the control sensitivity coefficient, and the following formula: Kd = (k4 / Sen) × Y + k5, Where k4 is a constant term, Kd is the first differential coefficient, and Y is the initial duty cycle; when the initial duty cycle is less than or equal to a preset first duty cycle threshold, and / or greater than or equal to a second duty cycle threshold, the first proportional coefficient is determined to satisfy the following formula based on the control sensitivity coefficient: Kp = k6 × Sen, Where k6 is the first preset constant term, and the value of k6 when the initial duty cycle is less than or equal to the first duty cycle threshold is less than the value of k6 when the initial duty cycle is greater than or equal to the second duty cycle threshold; Kp is the first proportional coefficient, and Sen is the control sensitivity coefficient; And / or, when the initial duty cycle is less than or equal to a first duty cycle threshold, and / or greater than or equal to a second duty cycle threshold, the first differential coefficient satisfies: Kd = k7 Where k7 is the second preset constant term, and Kd is the first proportional coefficient; wherein, when the initial duty cycle is less than or equal to the first duty cycle threshold, the value of k7 is less than the value of k7 when the initial duty cycle is greater than or equal to the second duty cycle threshold; The first integral coefficient is determined based on the first proportional coefficient; The first integral coefficient is determined by the following formula: Ki = Kp / k3, Where k3 is a constant term, Ki is the first integral coefficient, and Kp is the first proportional coefficient.

2. The temperature control method according to claim 1, characterized in that, Obtaining the control sensitivity coefficient of the heating device at the target temperature includes: Obtain the first derivative of the initial duty cycle of the heating device with respect to the target temperature, and use the first derivative as the control sensitivity coefficient.

3. The temperature control method according to claim 1, characterized in that, Before adjusting the current temperature based on the algorithm coefficients and using a proportional-integral-differential algorithm to bring the current temperature to the target temperature, the method further includes: In response to a control command to heat to the target temperature, the system performs heating at full load power. Determine whether the absolute value of the difference between the current temperature and the target temperature is less than or equal to a first preset threshold. If the absolute value of the difference between the current temperature and the target temperature is less than or equal to the first preset threshold, then the process of "adjusting the current temperature based on the algorithm coefficients and using a proportional-integral-differential algorithm" is executed. And / or, after adjusting the current temperature based on the algorithm coefficients and using a proportional-integral-differential algorithm, the method further includes: Determine whether the absolute value of the difference between the current temperature and the target temperature is less than or equal to a second preset threshold within a preset time period; If so, it confirms that the market has entered a stable phase; When entering the stable phase, temperature control is performed using a different combination of proportional-integral-derivative (PID) parameters than in the control phase where the current temperature is controlled based on a proportional-integral-derivative (PID) algorithm. In this combination, at least one parameter has a value less than the corresponding parameter value in the control phase.

4. The temperature control method according to any one of claims 1-3, characterized in that, The regulation of the current temperature based on the algorithm coefficients and using a proportional-integral-differential algorithm includes: The initial value of the cumulative deviation in the proportional-integral-differential algorithm is determined based on the ratio of the initial duty cycle to the preset integration parameter. Based on the initial value of the cumulative deviation and the algorithm coefficients, the current temperature is controlled using a proportional-integral-differential algorithm. And / or, the temperature control using a combination of proportional-integral-derivative (PID) parameters different from the control phase based on the PID algorithm for regulating the current temperature includes: When the absolute value of the difference between the current temperature and the target temperature is less than or equal to the second preset threshold, the temperature is controlled by the first proportional-integral-derivative parameter combination. When the absolute value of the difference between the current temperature and the target temperature is greater than the second preset threshold and less than or equal to the third preset threshold, temperature control is performed using a second proportional-integral-derivative (PID) parameter combination, wherein at least one parameter in the second PID parameter combination has a value greater than the value of the corresponding parameter in the second PID parameter combination.

5. A control device, comprising a processor and a storage device, said storage device being adapted to store a plurality of computer programs, characterized in that, The computer program is adapted to be loaded and run by the processor to perform the temperature control method according to any one of claims 1 to 4.

6. A computer-readable storage medium storing a plurality of computer programs, characterized in that, The computer program is adapted to be loaded and run by a processor to perform the temperature control method according to any one of claims 1 to 4.

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